US 12,333,846 B2
Apparatus with ultrasonic fingerprint sensor and one or more resonators, and related systems and methods
Jessica Liu Strohmann, Cupertino, CA (US); Hrishikesh Vijaykumar Panchawagh, Cupertino, CA (US); Nai-Kuei Kuo, Los Gatos, CA (US); Yipeng Lu, Moraga, CA (US); Ali Lopez, Dublin, CA (US); and Kostadin Dimitrov Djordjev, Los Gatos, CA (US)
Assigned to QUALCOMM Incorporated, San Diego, CA (US)
Filed by QUALCOMM Incorporated, San Diego, CA (US)
Filed on Nov. 17, 2023, as Appl. No. 18/513,144.
Application 18/513,144 is a continuation of application No. 17/448,031, filed on Sep. 17, 2021, granted, now 11,823,483.
Prior Publication US 2024/0161533 A1, May 16, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. G06V 40/13 (2022.01); G06F 21/32 (2013.01); H03H 9/17 (2006.01)
CPC G06V 40/1306 (2022.01) [G06F 21/32 (2013.01); H03H 9/17 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An apparatus, comprising:
an ultrasonic sensor stack; and
an acoustic resonator, comprising:
a first higher-impedance layer;
a second higher-impedance layer; and
one or more low-impedance layers residing between the first higher-impedance layer and the second higher-impedance layer, each of the one or more low-impedance layers having a lower acoustic impedance than an acoustic impedance of the first higher-impedance layer or an acoustic impedance of the second higher-impedance layer, at least one of the one or more low-impedance layers having a thickness corresponding to a multiple of a quarter wavelength at a peak frequency of the acoustic resonator.